Added support to the ReturnLinkPrefix and ReturnLinkSuffix attributes to
define HTML to display before and after the return links to go to other
sections like the entry listing, editing and deleting pages.

Made the MapNull column property take priority on the Format property if
the respective column is undefined.
Added support to the Replace column property to provide an array of regular
expressions to replace column values.

Added support to display the validation error message and the preview area
independently of the form header.
Added support to set the form header, form footer and error message format
properties when adding the input.